This invention relates to an apparatus which can controllably administer a parenteral liquid. More particularly, this invention relates to an intravenous administration set which will revert to a different or keep-vein-open (KVO) flow rate when the solution in a container empties.
In the administration of parenteral liquids, the source of parenteral liquid will eventually be exhausted. Unless a constant surveillance is made during the administration, in many instances the source of liquid will become depleted to the patient with the needle in communication wtih the vein. When this occurs, blood can coagulate around the needle thus effecting a blockage of the end of the needle or the situs where the needle enters the vein. In order to then effect flow when a new solution container is attached, the needle would have to be withdrawn and reinserted at a new site. A unit which is provided to obviate the foregoing adverse effects and to afford a different flow rate in a parenteral liquid is described by Price in U.S. Pat. No. 3,738,361. However, this particular unit requires precise positioning of moving parts which is costly to manufacture and can cause problems during usage.
It is an advantage of the present invention to provide a novel administration apparatus for a parenteral liquid which has a keep-vein-open means. Other advantages are an apparatus for administering I.V. liquids which affords two different flow rates with means which are easy to fabricate and afford positive and reliable functions; an I.V. administration unit which not only can afford different flow rates but can do so without utilizing moving parts or in some instances with a minimum of moving parts; an apparatus which can accomplish a keep-vein-open effect without moving parts and which affords an added advantage of filtering out particulate matter as well as air or gases; a device which in certain embodiments will retain a level of I.V. liquid in the sight chamber and tubing even when the KVO reservoir empties thus avoiding a new venipuncture.